A deadly Ebola outbreak in Africa is having a big impact on a family in Canmore.

Kayt and Stefan Mahon legally adopted Leo and Grace, who are twins, from an orphanage in Sierra Leone last February. However, the Ebola outbreak has crippled civil infrastructure and health-care systems, and the Sierra Leone government has not been able to provide the twins with the Sierra Leone passports they need to leave the country.

The Mahons say they are worried for the twins' health if they have to stay longer in Sierra Leone.

"The children themselves are quite safe from the virus, you know, but their health is in danger in so many ways because there's malaria, [hepatitis A], [hepatitis B], typhoid, breaking an arm, breaking a leg," said Stefan Mahon. "The effect of Ebola on the country has now crippled the medical system."

The Mahons say they are urgently appealing to the Canadian government to give their adopted twins citizenship so that they can get out of Sierra Leone.

Epidemic is international emergency, WHO says

Nearly 400 people are believed to have died of Ebola in Sierra Leone since the outbreak began in December 2013.

Earlier this month, the World Health Organization declared the outbreak an international public health emergency and called on the international community to provide support for the affected countries.

The WHO says the governments of Guinea, Liberia, Sierra Leone and Nigeria don't have the capacity to manage an outbreak of this size and complexity.

There are no licensed drugs or vaccines for the viral disease, which has a fatality rate of up to 90 per cent.

People who contract Ebola are not contagious until they show symptoms, say health experts.